The present invention relates to a method for detecting codes applied to copies being screened in a microfilm camera and a corresponding microfilm camera.
Methods for detecting codes applied to the copies being screened normally comprise a code reader which reads various blips applied to the film and corresponding to various images of the original copies.
A method and a microfilm camera of the type under consideration have been disclosed, for example in DE-PS No. 33 03 647. In this method, blips applied to the microfilm are continually counted and the so-produced image numbers correspond to the code corresponding to the image on the original copy, whereby the code is examined, and the image reception or further processing are carried out when the accuracy of the codes is proven. When the copy having no code or unknown or erroneous code enters the microfilm camera the screening process is interrupted. It is not possible to screen selectively coded and uncoded original copies and to apply blips of various types or no blips to the film at will. Further, the speed of the screening is also limited by the continual counting of the blips and the direct correspondence of the counter outputs to individual original copies or their codes and addresses and not only by the stopping of the camera during the processing of uncoded or falsely-coded copies.